Automatic fire-alarm.



PATENTED AUG. 22, 1905.

K. J. BAQKMAN. AUTOMATIC FIRE ALARM.

APPLICATION TILED THE. 7, 1905.

KARL J OHAN BAOKMAN, OF KARLSVIK, FORSHAGA, SWEDEN.

AUTOMATIC FIRE-ALARM.

Specification of Letters Patent.

Patented Aug. 22, 1905.

Application filed February 7,1905. Serial No. 24 L621.

To all whom it may concern:

Be it known that I, KARL JOHAN BAGKMAN, acitizen of Sweden, residing at Karlsvik, Forshaga, Sweden, have invented new and useful Improvements in Automatic Fire-Alarms, of which the following is a specification.

The present invention relates to an automatic fire-alarm which is especially suitable to be combined with an electric hell, but which can of course be put in any kind of electric circuit being in connection with some suitable alarm'apparatus. It has .the advantage of being comparatively cheap in construction at the same time that it is durable and effective and is easily placed into position and, if necessary, moved to another place.

The characteristic feature of the invention consists therein that oneof two contacts. which, as usual, are separated from each other by an easily-fusible substance and which has a tendency to come into contact with each other, is formed into a cup for containing the fusible substance.

The accompanying drawings show as an example a form of construction of the apparatus in question.

Figure 1 shows the apparatus in longitudinal section, and Fig. 2 gives a front view of it.

The apparatus as here shown is intended to be combined with an ordinary electric bell.

A bracket 1, made of some conducting material, is provided with a clamp-screw 2 in order to screw fast the. wire of the one pole. On this bracket lies one end of a springy and conducting arm 3 and upon this a piece 4, of some insulating material, and on this latter the one end of another spring and conducting arm 5, all of these being held together by the screws 6, which are isolated from the arm 5. In the conducting part 7, which is placed on the isolating-piece 4. and which is in electric contact with the arm 5, there is screwed fast the other clamp-screw 9 for clamping the wire of the second pole. The outer end of the arm 3 is formed into a little cup 10, which is filled with an easily-fusible substance 11, such as wax, stearin, or such like. The cup 10 has a contact 12, of copper, soldered or nailed fast to its bottom. In order to obtain more springiness, the arm 3 is bent into the form shown on Fig. 1, and it has a contact 8, of copper, fastened to its outer end. This latter contact in consequence of the elasticity of the two arms is held pressed against the easily-fusible substance in the cup and preferably is embedded in this substance. By both contacts being thus embedded in the easily fusible substance the advantage is gained that the surfaces of the contacts are kept clean and free from oxidation. The cup should preferably be provided with an exterior surface strongly absorbent of radiating warmth. Should fire arise in a room provided with such an apparatus, it is only necessary that the temperature rises to the melting-point of the substance in the cup for the electric circuit to be closed, whereupon the bell begins to ring, and should a numberplate be used notice is given in which room fire has broken out.

The apparatus can of course be constructed in a number of different ways, care only being taken to retain the characteristic features of the invention. The cup can clearly be of any form and size and be made in any way which is found suitable. The contact in the bottom of the cup can consist of the bottom of the cup itself, which bottom must then be of a substance and form suitable for the purpose.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. In a thermostatic circuit-closer, a cup, a contact arranged at the bottom thereof and forming one terminal of the circuit, a second contact partly extending within the cup, a spring carrying the second contact and tending to move it toward the first contact, and a fusible block of non-conducting material arranged within the cup and protecting both contacts from oxidation, said fusible material being displaced by the spring when softened by exposure to high temperature.

2. In a device of the class specified, a bracket member, a strip extending therefrom and provided near its outer end with a cup containing a readily-fusilfle non-conducting material, a contact at the lower portion of the cup, a block of insulating material mounted on the strip, a spring-strip mounted on the block of insulating material, and a pin carried by the spring-strip and having its outer end embedded in said fusible material, substantially as specified.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

KARL JOHAN BAOKMAN.

Witnesses: I

M. SJUBERG, JAs. MALL. 

